The present invention relates to the production of silicate melts, and more particularly, to a glassmaking tank furnace.
Extensive use has been made of glassmaking tank furnaces, each of which comprises a basin, a heating system, a housing including a roof and a gas flue, as well as a feed port and a discharging port.
For example, French Pat. No. 128,488 discloses a glassmaking tank furnace, the all-metal basin of which is spray-cooled and is lined with a refractory. In some furnaces (cf. U.S.S.R. Inventor's Certificate No. 264,636), a direct-expansion system is used for cooling the basin refractory lining, which system incorporates upright tubes brought in communication with the upper and lower collector mains. The cooling system in question ensures the continuous and reliable operation of basins employed in tank furnaces.
Long service life of tank furnaces, however, is hindered by insufficient strength of the furnace housing at the area of its end wall fitted with a feed port opening. In addition, due to the lack of sufficiently resistant refractories used for the bottom and walls of the furnace basin, it is impossible to further intensify the melting process by subjecting the melt to electrical heating or causing its bubbling, in view of the modern tendency of making the furnace basins smaller in depth. The problem is further complicated by the fact that as refractories are destroyed by agressive melts they contaminate the end product, thereby impairing its quality.
Moreover, in the course of producing high-temperature melts in the tank furnace, there arises a problem of making effective use of the heat liberated from the off gases, which is mainly due to the difficulty of installing heat-employing equipment immediately behind the furnace, since, more often than not, the procedure of using the heat from the off gases invariably required preliminary cooling of the combustion products to adequate temperatures.